What did Christ accomplish for us at the cross?
At the cross, Christ finished every single demand of God on a sinful person. He alone kept the whole Law, which no one else could do. He took all guilt away from the person the moment he believed that Christ died and rose from the dead.
Les explains that if a person adds legalistic requirements, such as circumcision, to the Gospel, then Christ profits them nothing. The reason is that God is jealous of what He accomplished on our behalf. At the cross He finished every single demand of God on a sinful person, and He would take all that guilt away from that person the moment he believed that Christ died and rose from the dead. Only Christ Himself ever kept the whole Law; no one else has been able to do it. Les presents this as logical because God has done so much.